如何屏蔽EditText以显示dd/mm/yyyy日期格式

Question

我如何格式化EditText以遵循" dd/mm/yyyy"格式,就像我们可以使用a TextWatcher来屏蔽用户输入看起来像"0.05€"一样.我不是在谈论限制字符,或者验证日期,只是掩盖了以前的格式.

Answer 1

我TextWatcher为一个项目写了这个,希望它对某人有帮助.需要注意的是它并没有验证用户输入的日期,你应该处理时的焦点变化,因为用户可能无法完成输入的日期.

更新25/06制作一个wiki,看看我们是否达到了更好的最终代码.

更新07/06 我终于为观察者本身添加了某种验证.它将执行以下无效日期:

• 如果月份大于12,则为12(12月)
• 如果日期大于所选月份的日期,请将其作为该月份的最大值.
• 如果年份不在范围内1900-2100,请将其更改为范围

这个验证符合我的需要,但你们中的一些人可能想稍微改变一下,范围很容易改变,你可以将这种验证挂钩到Toast例如消息,以通知用户我们已经修改了他/她的日期,因为它是无效.

在这段代码中,我会假设,我们对我们的参考EditText称为date已此TextWatcher连接到它,这是可以做到这样的事:

EditText date;
date = (EditText)findViewById(R.id.whichdate);
date.addTextChangedListener(tw);

TextWatcher tw = new TextWatcher() {
    private String current = "";
    private String ddmmyyyy = "DDMMYYYY";
    private Calendar cal = Calendar.getInstance();

当用户更改文本时 EditText

    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {
        if (!s.toString().equals(current)) {
            String clean = s.toString().replaceAll("[^\\d.]|\\.", "");
            String cleanC = current.replaceAll("[^\\d.]|\\.", "");

            int cl = clean.length();
            int sel = cl;
            for (int i = 2; i <= cl && i < 6; i += 2) {
                sel++;
            }
            //Fix for pressing delete next to a forward slash
            if (clean.equals(cleanC)) sel--;

            if (clean.length() < 8){
               clean = clean + ddmmyyyy.substring(clean.length());
            }else{
               //This part makes sure that when we finish entering numbers
               //the date is correct, fixing it otherwise
               int day  = Integer.parseInt(clean.substring(0,2));
               int mon  = Integer.parseInt(clean.substring(2,4));
               int year = Integer.parseInt(clean.substring(4,8));

               mon = mon < 1 ? 1 : mon > 12 ? 12 : mon;
               cal.set(Calendar.MONTH, mon-1);
               year = (year<1900)?1900:(year>2100)?2100:year;
               cal.set(Calendar.YEAR, year); 
               // ^ first set year for the line below to work correctly
               //with leap years - otherwise, date e.g. 29/02/2012
               //would be automatically corrected to 28/02/2012 

               day = (day > cal.getActualMaximum(Calendar.DATE))? cal.getActualMaximum(Calendar.DATE):day;
               clean = String.format("%02d%02d%02d",day, mon, year);
            }

            clean = String.format("%s/%s/%s", clean.substring(0, 2),
                clean.substring(2, 4),
                clean.substring(4, 8));

            sel = sel < 0 ? 0 : sel;
            current = clean;
            date.setText(current);
            date.setSelection(sel < current.length() ? sel : current.length());
        }
    }

我们还实现了其他两个功能,因为我们必须这样做

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {}

    @Override
    public void afterTextChanged(Editable s) {}
};

这会产生以下效果,删除或插入字符将显示或隐藏dd/mm/yyyy蒙版.应该很容易修改以适应其他格式的掩码,因为我试图让代码尽可能简单.

Answer 2

目前的答案非常好,并帮助指导我自己的解决方案.我决定发布自己的解决方案有几个原因,即使这个问题已经有一个有效的答案:

• 我在Kotlin工作,而不是Java.发现自己遇到同样问题的人将不得不翻译当前的解决方案.
• 我想写一个更清晰的答案,以便人们可以更容易地适应他们自己的问题.
• 正如dengue8830所建议的那样,我在一个类中封装了这个问题的解决方案,所以任何人都可以使用,甚至不用担心实现.

要使用它,只需执行以下操作:

• DateInputMask(mEditText).听()

解决方案如下所示:

class DateInputMask(val input : EditText) {

    fun listen() {
        input.addTextChangedListener(mDateEntryWatcher)
    }

    private val mDateEntryWatcher = object : TextWatcher {

        var edited = false
        val dividerCharacter = "/"

        override fun onTextChanged(s: CharSequence, start: Int, before: Int, count: Int) {
            if (edited) {
                edited = false
                return
            }

            var working = getEditText()

            working = manageDateDivider(working, 2, start, before)
            working = manageDateDivider(working, 5, start, before)

            edited = true
            input.setText(working)
            input.setSelection(input.text.length)
        }

        private fun manageDateDivider(working: String, position : Int, start: Int, before: Int) : String{
            if (working.length == position) {
                return if (before <= position && start < position)
                    working + dividerCharacter
                else
                    working.dropLast(1)
            }
            return working
        }

        private fun getEditText() : String {
            return if (input.text.length >= 10)
                input.text.toString().substring(0,10)
            else
                input.text.toString()
        }

        override fun afterTextChanged(s: Editable) {}
        override fun beforeTextChanged(s: CharSequence, start: Int, count: Int, after: Int) {}
    }
}

Answer 3

使用JuanCortés代码的更简洁方法是将其放在一个类中：

public class DateInputMask implements TextWatcher {

private String current = "";
private String ddmmyyyy = "DDMMYYYY";
private Calendar cal = Calendar.getInstance();
private EditText input;

public DateInputMask(EditText input) {
    this.input = input;
    this.input.addTextChangedListener(this);
}

@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {

}

@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
    if (s.toString().equals(current)) {
        return;
    }

    String clean = s.toString().replaceAll("[^\\d.]|\\.", "");
    String cleanC = current.replaceAll("[^\\d.]|\\.", "");

    int cl = clean.length();
    int sel = cl;
    for (int i = 2; i <= cl && i < 6; i += 2) {
        sel++;
    }
    //Fix for pressing delete next to a forward slash
    if (clean.equals(cleanC)) sel--;

    if (clean.length() < 8){
        clean = clean + ddmmyyyy.substring(clean.length());
    }else{
        //This part makes sure that when we finish entering numbers
        //the date is correct, fixing it otherwise
        int day  = Integer.parseInt(clean.substring(0,2));
        int mon  = Integer.parseInt(clean.substring(2,4));
        int year = Integer.parseInt(clean.substring(4,8));

        mon = mon < 1 ? 1 : mon > 12 ? 12 : mon;
        cal.set(Calendar.MONTH, mon-1);
        year = (year<1900)?1900:(year>2100)?2100:year;
        cal.set(Calendar.YEAR, year);
        // ^ first set year for the line below to work correctly
        //with leap years - otherwise, date e.g. 29/02/2012
        //would be automatically corrected to 28/02/2012

        day = (day > cal.getActualMaximum(Calendar.DATE))? cal.getActualMaximum(Calendar.DATE):day;
        clean = String.format("%02d%02d%02d",day, mon, year);
    }

    clean = String.format("%s/%s/%s", clean.substring(0, 2),
            clean.substring(2, 4),
            clean.substring(4, 8));

    sel = sel < 0 ? 0 : sel;
    current = clean;
    input.setText(current);
    input.setSelection(sel < current.length() ? sel : current.length());
}

@Override
public void afterTextChanged(Editable s) {

}
}

那你就可以重用

new DateInputMask(myEditTextInstance);

Answer 4

尝试使用解决此问题的库，因为屏蔽它不能开箱即用。有很多极端情况（比如在已经屏蔽的文本中间添加/删除字符），要正确处理这个问题，您最终会得到很多代码（和错误）。

以下是一些可用的库：
https://github.com/egslava/edittext-mask
https://github.com/dimitar-zabaznoski/MaskedEditText
https://github.com/pinball83/Masked-Edittext
https://github .com/RedMadRobot/input-mask-android
https://github.com/santalu/mask-edittext

** 请注意，在编写这些库时并非没有问题，因此您有责任选择最适合您的库并测试代码。